In recent years, sizes of digital data recorded on optical recording media have been increased with the availability of highly defined images and movies. Such trends strengthen the demand for a recording media with a higher capacity. As a high capacity optical recording media, BD which is capable of storing 50 GB data by the multi-layer recoding method is already commercially available. In the above-mentioned BD, improvement of the currently available capacity is expected. Thus, research is conducted vigorously for obtaining even higher capacity by multi-stratifying the recoding layer.